OFFSET
1,1
COMMENTS
A histogram of the first 1.4 million terms in this sequence reveals 7 as the most common term with a frequency of 15.25%. The smaller primes (2, 3, and 5) occur with frequencies between 12% and 14%, and larger primes rapidly decrease in frequency. 99% of the terms are composed of the first 20 primes (2, 3, 5, ..., 71). The largest of the first 1.4 million terms is a(220693) = 281, which is the sum of an otherwise prime-free sum of 64 consecutive digits of Pi (6 + 9 + 3 + 9 + 5 + 4 + 6 + 9 + 7 + 5 + 5 + 9 + 9 + 6 + 4 + 0 + 0 + 8 + 2 + 9 + 7 + 6 + 0 + 0 + 5 + 3 + 5 + 4 + 1 + 8 + 8 + 6 + 6 + 1 + 7 + 8 + 8 + 2 + 3 + 1+ 1 + 1 + 0 + 2 + 0 + 1 + 7 + 2 + 7 + 1 + 5 + 5 + 7 + 3 + 0 + 2 + 2 + 5 + 5 + 0 + 5 + 9 + 5 + 2).
EXAMPLE
a(1) = 3 because it is the first digit of Pi, and it is prime.
a(2) = 1 + 4 = 5 because it is the sum of the next consecutive digits of Pi, and it is prime, and the prior sum (1) is not prime.
a(3) = 1 + 5 + 9 + 2 = 17 because it is the sum of the next consecutive digits of Pi, and it is prime, and prior sums (1, 1 + 5 = 6, 1 + 5 + 9 = 15) are not prime.
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Gil Broussard, Aug 15 2014
STATUS
approved